(a) Field of the Invention
The present invention relates to means for indicating the residual gas volume of a gas storage means and more particularly to a gas cylinder residual gas volume indicator, which indicates the residual gas volume of a gas cylinder by means of a hydraulic mechanical operation.
(b) Description of the Prior Art
Regular gas ovens or gas grills use fuel gas for producing heat energy. Fuel gas must be contained in a gas cylinder (made of steel) for delivery, storage and use. However, a user may not know the actual residual gas volume. The fuel gas of a gas cylinder may be fully used up in the middle of baking or cooking, causing embarrassment and inconvenience. In view of this problem, meters capable of indicating the residual gas volume of a gas cylinder are created. These conventional indicating meters for residual gas volume are battery-operated electronic meters. However, electronic meters tend to be interfered by external noises. Further, electronic meters commonly have a complicated structure. Further, electronic meters are expensive and not always affordable for consumers.